Air washer



March 25, 1952- AIR WASHER C. F. NIEHAUS ETAL Filed June 24, 1947 IN VEN TORS CARL'F.' NIEHAUS and BY, WILLIAM G. NIEHAUS 7 A TTORNEl/Patented Mar. 25, 1952 O F FICE AIR WdSHER Carl' F. Niehaus and WilliamG. lllieiiaus, Indianapolis, Ind.

Applicatien June 24, 1947,-Seria1 N0. 756,612

4 Ciaims.

,I The present invention relates to a device for cleansing contaminatedair in which an impeller fan, rotating at high speed, atomizes a streamof washing liquid to produce a fog of tiny liquid particles, sets up ahigh-speed rotation of that fog, and simultaneously forces the gaseousfluid to be washed, to flow through that fog.

It is a primary object of the present invention to cleanse contaminatedair before allowing it to escape into the atmosphere. A further objectof the invention is to effect centrifugal separation of relatively heavymaterials entrained` in the atmosphere; and a still further object is toprovide mechanism embodying certain novel features of construction', tocarry out most effectively the above-mentioned objects.

The disclosed embodiment of this invention is particularly adaptable asan exhaust apparatus for electroplating baths from which emanate variousgases and finely-divided solids which have a deleterious effect onmachinery, personnel, and materials in the immediate vicinity. Whenutilized in this particular manner, the various gases and suspendedsolids are substantially completely separated from the air and carriedto Waste, or to a suitable collecting station, the cleansed air beingexhausted to the atmosphere.

To the accomplishment of the above and related objects, our inventionmay be embodied in the form illustrated in the accompanying drawings,attention being called to the fact, however, that the drawings areillustrative only, and that change may be made in the specificconstruction illustrated and described, so long as the scope of theappended claims is not violated.

Fig. 1 is a vertical section of the disclosed embodiment of the presentinvention; and

Fig. 2 is a sectional view ofthe same embodiment taken substantially online 2-2 of Fig. 1.

Referring more particularly to Fig. 1 of the drawings, it will be seenthat a suitable frame I 0, having three legs I I held in xed relation bythe horizontally disposed rigid braces I2, supports a drum or tank I8having a closed bottom I9 through which opens a discharge conduit 20,and through which extends a vertical shaft 2| of electric motor 22bolted to said braces upon which is mounted a centrifugal fan 23 closedat its bottom 24 and centrally open at its top 25. An air intake conduit23, centrally supported within drum or tank I8 by means of a pair ofvertically spaced horizontal spiders 21 and 28, registers with the openend 25 of the fan 23; and a water inlet conduit 29, suitably supportedwithin conduit 26 and projecting,

high speed, atomizing the washing liquid which owsthrough perforations32 in conduit 29 and filling the lower portion of chamber 33 with a fogoftiny droplets'. The contaminated air,

drawn by fan 23 through the conduit 26 and discharged with a swirlingmotion into the chamber 33, must pass through that fog before escapingpast the inwardly projectingv peri-pheral flange 3=l secured to the top35 of drum I8. The high speed rotating motion of the fan induces asimilar movement of the atmosphere within the chamber` 33, causing amechanical centrifugal separation of the washing uid and contaminatingparticles from the air. Concurrently, the droplets of washing liquid arebrought into intimate contact withl gases and solids dissolved orsuspended in the air, and gasesA soluble in such liquid, as well as dustparticles and the like are absorbed or centrifugally separated from thea1r.

We have found in practice that a substantial degree of cleansing can beeffected through the use of the disclosed mechanism even when no washingliquid is supplied through the conduit 29, because of the centrifugalaction above-described.

An important feature of our invention is embodied in the flange 34 whichserves to prevent the fog from escaping with the washed air. Condensateformed on the underside of this ange and on the inner wall of chamber 33ows down such wall and is collected in the bottom I9 and drained outthrough conduit 2l).

The collection of liquid on the side walls of the chamber 33 is largelycaused by centrifugal separation of moisture particles due to thehighspeed rotation of the atmosphere within said chamber set up by theaction of the fan. In operation, it is found that a considerablequantity of liquid gathers, at the periphery of the bottom I9 of thechamber 33, in the form of an annulus having a concave inner surface,and extending a substantial distance up the side walls of the chamber.

The flange 34 provides a space of negligible air iiow immediatelybeneath it which prevents the discharging air from carrying condensedcondensate up the chamber Walls and out into the atmosphere.

Of further substantial importance is our discovery that the internalsurfaces of the upstanding Walls of the chamber 33 must be formed ofmaterial which is wettable by the selected washing liquid. We have foundthat certain coatings; when applied to those walls, will result in thecreation of droplets of liquid standing separately upon the coatings andsubject to entrainment in the rapidly flowing stream of cleansed airmoving toward the discharge end of the mechanism. A very decidedreduction in the efciency of the unit was found to result from theapplication oi' such coatings; and the optimum eiflciency was found tobe restored only when materials wettable by the selected washing liquidwere used to form the inner surfaces of said upstanding chamber walls.Illustrative, but not exclusive, examples of such materials for use whenwater is selected for the washing liquid, are bare steel, stainlesssteel, wood, or any of those materials when covered with coatings whichare, themselves, Wettable by water. Such coatings, however, providelittle advantage since, by their very characters, they are subject togradual destruction and removal by the flowing washing liquid.

If desired, the conduit may lead to an auxiliary sump tank, whenceliquid drained Jfrom the chamber 33 may be passed through suitable puri-`fying processes and then recirculated to the conduit 29. In casevaluable materials are dissolved or entrained in the washing liquid,such materials may thus be recovered in one ci' more of such purifyingprocesses.

We claim as our invention:

1. An air cleansing device comprising a vertically arranged casinghaving an annularly open top and a closed bottom, a conduithaving openends concentrically xedly secured in said casing with one end of saidconduit disposed near the bottom of said casing and the other end ofsaid conduit projecting through and beyond said casing open top, saidconduit being spaced from the perimeter of said casing to dennetherewith a vertically-extending chamber open at its top, a shaftjournalled for rotation upon a vertical axis and centrally projectingthrough said casing bottom, means for driving said shaft at high speed,a centrifugal fan carried on said shaft within said casingandregistering with said one end of said conduit, said fan being arrangedand adapted to draw air downwardly through said conduit and to dischargeair radially into said chamber for upward flow to and through said opentop of said casing to the atmosphere, and means disposed adjacent thecenter of rotation of said fan for continuously delivering liquid tosaid fan for discharge therefrom with such air.

2. The device of claim 1 in which said ian comprises a flat plate normalto, and coaxially mounted upon, said shaft, a series of blades arrangedabout the periphery of said plate, radially spaced from said shaft axis,projecting in a common direction from said plate in parallelism withsaid shaiil axis, and annularly-continuous means secured to and joiningsaid blades at their ends remote from said plate.

3. The device of claim 2 in which said liquiddelivering means extendsinto proximity with said plate in the region enclosed by said bladeseries and between said plate and the plane of the joined remote ends ofsaid blades.

4. The device of claim 3 in which said liquiddelivering means includes anozzle located in said region, closed at its end adjacent said plate,and provided with a plurality of minute, radially-directed openingsthrough which liquid is delivered in a spray directed toward saidblades.

CARL F. NIEHAUS.

WILLIAM. G. NIEI-IAUS.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 632,370 Rossler Sept. 5, 1899772,655 Fries Oct. 18, 1904 831,275 Fries Sept. 18, 1906 991,157 KestnerMay 2, 1911 1,894,864 Hall Jan. 17, 1933 1,980,522 Hawley Nov. 13, 19342,254,600 Ditto Sept. 2, 1941 FOREIGN PATENTS Number Country Date 25,559Great Britain Nov. 18, 1907

